Ciccariello-Maher, who teaches politics at Drexel University, tweeted Sunday: "Some guy gave up his first class seat for a uniformed soldier. People are thanking him. I'm trying not to vomit or yell about Mosul." Ciccariello-Maher's account is private, but screenshots of his tweet were shared by others, many of whom were critical.

Ciccariello-Maher wrote on Facebook Thursday that he respects soldiers, but doesn't respect U.S. actions in Iraq. He wrote: "Maybe predictably, my tweet has since been fed into and misrepresented by the outrage machine that is right-wing media. Needless to say, my personal views expressed off-campus have absolutely nothing to do with those of my employer, Drexel University."

In a statement, Drexel said that the professor's comments "do not represent the University's views."

Ciccariello-Maher also faced criticism in December for tweeting, "All I Want for Christmas is White Genocide," a post he said was satirical.